Phosphor copper alloys are utilized in the metal and metal melting industry to remove oxygen trapped in the molten metal, to increase the fluidity of the molten metal, and remove unwanted impurities in the molten metal. Phosphorous is a good deoxidizer due to its strong affinity for oxygen. Phosphor copper has been used for deoxidizing metals in the past on the belief that the master alloy is easier and safer to handle than elemental phosphorous.
The most common type of phosphor copper alloy contains approximately 15% phosphorous and 85% copper.
U.S. Pat. No. 2,164,228 (Burns) discloses a batch-wise method of adding liquid phosphorous, which is immersed in a body of water, to a crucible or pot of molten metal to produce phosphorous alloys. There is no mention of adding the liquid phosphorous at any particular rate or treating the molten metal for excess oxygen.
U.S. Pat. No. 3,844,772 (Sherman) discloses injecting liquid methanol into molten copper. There is no mention of adding liquid phosphorous to the molten copper, nor is there any mention of the rate at which the liquid methanol is added to the molten copper.
U.S. Pat. No. 3,528,803 (Ichikawa et al.) discloses the addition of ingot, plate, rod, chip, grain, or powder forms of phosphorous or phosphorous alloys in molten copper to remove hydrogen. This is no mention of the addition of liquid elemental phosphorous to molten copper.
U.S. Pat. No. 2,098,063 (Perrin) discloses adding liquid metaphosphoric acid into a pouring jet of copper.
British Patent No. 1,552,153 (Elton) discloses removing copper from lead and lead alloys by adding phosphorous to the melt at intervals. The intervals between additions are such that the reaction caused by the previous addition has been completed prior to the next addition of phosphorous. However, the phosphorous is not in liquid form.